Scalable telecommunications system

ABSTRACT

One aspect is directed to a node unit for a scalable telecommunications system. The node unit is configured to have inserted therein a respective power amplifier module and duplexing module for each of a plurality universal digital RF transceiver modules. The node unit is configured to communicatively couple an input of each power amplifier module to an output of the respective universal digital RF transceiver module. The node unit is configured to communicatively couple each universal digital RF transceiver module to respective external equipment via a duplexing module. At least one module comprises a module identifier. The system controller is configured to read the at least one module identifier and to configure the operation of at least one of universal digital RF transceiver modules, universal digital transport interface modules, and universal backplane module based on the at least one module identifier.

CROSS-REFERENCE TO RELATED APPLICATIONS

A priority claim is hereby made to U.S. Provisional Application Ser. No.62/182,063, filed Jun. 19, 2015, and titled “Scalable TelecommunicationsSystem,” the contents of which are incorporated herein by reference.

BACKGROUND

Examples of telecommunications systems include distributed antennasystems (DAS's) and repeaters. The repeaters may be off-air repeaters.It is desirable for telecommunications systems to handle multipletechnologies, frequency bands, or operators.

Many conventional platforms are not adapted to be readily configured ormodified in the field, especially if the electrical equipment should beprotected against water and dust. Off-air repeater installations caninvolve receiving multiple frequency bands from base stations via one ormore donor antennas. The core of an off-air repeater 100 can be thefrequency independent, digital main board 102 where RF cards 104 areplugged in (see FIG. 1 and FIG. 2). Each RF card 104 itself comprisesthe RF interface for converting received analog RF signals from a basestation or user equipment into digital signals. The RF cards 104 alsoconvert received digital signals from the digital main board 102 back toanalog RF signals that are transmitted to a base station or userequipment. By design, each RF card 104 is tuned to a specific frequencyrange (e.g., in the GSM 900 band ranging from 880 MHz to 960 MHz) andcan include a duplexer for each of the donor and coverage ports of theRF card 104. Each duplexer separates transmit (TX) signals from thereceive (RX) signals (e.g., for the GSM 900 band, RX signals in thefrequency band from 880 MHz to 915 MHz and TX signals in the frequencyband from 925 MHz to 960 MHz). Other parts of each RF card 104 includethe final power amplifier in RX and TX chain, which amplify the relevantRF signals to a desired output power. The donor and coverage ports ofmultiple RF cards 104 are combined into one single donor port 108 andone single coverage port 110 of the repeater 100 using a combiner 106.Off-air repeaters can be installed indoors (e.g., small sized rooms,offices, venues, malls, etc.) and outdoors (e.g., urban, rural, etc.).The output power requirements can vary, depending on the installationenvironment. To cover the possible installations, at least 3 differentoutput power variants (e.g. 100 milliWatts (mW), 1 Watt (W), and 10 W)need to exist in parallel. Additionally, there are dozens of differentfrequency/operating bands for wireless communications worldwide, and itis expected that this number is increasing due to the required bandwidthand data throughput needs.

The number of different variants of RF cards (frequency and outputpower) can be numerous.

FIG. 2 depicts an example of a distributed antenna system (DAS) 200 thatincludes a master unit 202 and multiple remote units 204. The masterunit 202 can be communicatively coupled to one or more base stations 206by cables or other type of communication medium, including a wirelesscommunication medium. Within the master unit 202, multiple technologies,frequency bands, or operators can be separated, first into transmit (TX)and receive (RX) signals by duplexers 208 included in apoint-of-interface (POI) module 210, and then combined and split intoseveral common TX and RX paths by transmit and receivesplitter/combining matrices 212. The combined TX signals may beconverted into optical signals by optical transceivers (OTRX) 214 andthen fed to multiple remote units 204 via fibers 216. In other examples,communication media other than optical can be used. Within each remoteunit 204, the optical signals are received and converted back to RFsignals by an OTRX 218 in the remote unit 204. Each TX signal can be fedto a final amplifier 220. The individual TX signals can be combined in amultiplexer 222 and output on one or more RF ports 224 to serve thecoverage area. Similar processing is performed in the upstream orreceive direction.

The point of interface 210 within the master unit 202 is typicallyfrequency dependent and includes gain adjustment elements that typicallyneed to be adapted for the received input power of the respective thebase station 206. The remote units 204 may handle multiple frequencyband mixes and can be available in different output power classes. Thiscan lead to numerous variants of the master unit 202 and remote units204.

SUMMARY

Certain aspects and features relate to configurable platforms fortelecommunications systems that can be configured and scaled to meetchanging site requirements. In some examples, a telecommunicationssystem, such as a repeater or distributed antenna system for transportof signals for wireless coverage, is built from modules (e.g., buildingblocks) that can be easily swapped or added to handle different types ofsignals or provide different performance. The modules can be categorizedin different families of modules. Modules of the same family can havethe same form factor so that the modules can be easily swapped. Eachmodule can include identification information that can be detected by asystem controller to determine the type of module and the performancecharacteristic of the module. The system controller may alsoself-optimize the respective unit and adjust parameters via software. Asystem controller may be separate from the modules, or included in oneof the modules, such as a digital backplane module or a digitaltransport interface module.

Using certain examples can provide the ability to scale thetelecommunications system to handle new RF bands, for example, and tomake the system easy to assemble and modify in the field. For example,if a higher-power amplification is needed for a particular band, alower-power power amplifier module can be swapped with one having ahigher-power capability. Previously, separate components would beselected and integrated into the system. It was not possible to easilyreplace a component and have the system work.

The different families of modules can include power amplifier modules,digital filter element modules, digital radio frequency (RF) transceivermodules, digital transport interface modules, backplane modules, andcombiner modules.

Each module listed above can also include (i) interfaces to modules ofdifferent families and (ii) a controller or other mechanism (e.g., anRFID chip) for storing and outputting a module identification.

One may easily build a telecommunications system with differentcombinations of power amplification levels, capability of handlingdifferent frequency ranges, and digital transport interface capabilities(e.g., optical or electrical), depending on the needs for the particularsystem. A system controller can identify the modules and can modify, asneeded, the performance of the digital RF transceiver via software todeal with the particular other modules added.

One aspect is directed to a node unit for a scalable telecommunicationssystem. The node unit comprises a plurality of universal digital RFtransceiver modules, each of which is configured to communicativelycouple the node unit to respective external equipment. The node unitfurther comprises one or more universal digital transport interfacemodules, each of which is configured to communicatively couple the nodeunit to a respective transport link. The node unit further comprises auniversal backplane module communicatively coupled to the universaldigital RF transceiver modules and to the universal digital transportinterface modules. The node unit further comprises a system controller.The node unit is configured to have inserted therein a respective poweramplifier module and duplexing module for each universal digital RFtransceiver module. The node unit is configured to communicativelycouple an input of each power amplifier module to an output of therespective universal digital RF transceiver module. The node unit isconfigured to communicatively couple each universal digital RFtransceiver module to the respective external equipment via therespective duplexing module. At least one module comprises a respectivemodule identifier. The system controller is configured to read the atleast one module identifier and to configure the operation of at leastone of the universal digital RF transceiver modules, the universaldigital transport interface modules, and the universal backplane modulebased on the at least one module identifier.

The details of one or more aspects and examples are set forth in theaccompanying drawings and the description below. Other features andaspects will become apparent from the description, the drawings, and theclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example of a conventional off-airrepeater.

FIG. 2 is a block diagram of one example of a conventional distributedantenna system.

FIG. 3A is a block diagram of one example of a scalabletelecommunications system with a universal combining harness moduleinstalled.

FIG. 3B is a block diagram of one example of a scalabletelecommunications system without a universal combining harness moduleinstalled.

FIG. 3C is a block diagram illustrating various modules for a scalabletelecommunications system.

FIG. 4 is a block diagram of one example of a distributed antenna systembuilt with the modules and nodes units of FIGS. 3A-3C.

FIG. 5 is a block diagram of one example of a repeater architectureimplemented using the modules and node units of FIGS. 3A-3C.

FIG. 6 is a block diagram of one example of a system for scanning an RFspectrum.

DETAILED DESCRIPTION

FIGS. 3A and 3B are block diagrams illustrating one example of ascalable telecommunications system 300. The scalable telecommunicationsystem 300 shown in FIGS. 3A-3B comprises multiple nodes units 302. Eachnode unit 302 is communicatively coupled to at least one other node unit302 using one or more transport links.

Each node unit 302 includes one or more external ports 306 tocommunicatively couple the node unit 302 to external equipment. Examplesof external equipment include monolithic base station elements (such asa macro base stations, small-cell or femto-cell base stations, etc.),distributed base station elements (such as baseband units, remote radioheads, master eNodeBs, secondary eNodeBs, etc.), antenna-relatedequipment (such as bi-directional amplifiers, donor antennas, coverageantennas, etc.) and core-network elements (such as serving gateways(S-GW), mobility management entities (MME), etc.).

Each node unit 302 also includes one or more transport ports 308 tocommunicatively couple that node unit 302 to one or more other nodeunits 302 over one or more transport communication links. Example ofsuch transport communications links include one or more optical fibersand copper cables (such as twisted-pair category cables, and coaxialcables). Each node unit 302 can be coupled to another node unit 302using a single cable (for example, a single optical fiber using wavedivision multiplexing (WDM)) or multiple cables (for example, where afirst cable in used for transmitting signals from a first node unit 302to a second node unit 302 and a second cable is used for transmittingsignals from the second node 302 to the first node 302).

The node units 302 can be arranged into various systems and can be usedwith various combinations of power levels, frequency bands, andtechnologies.

Each node unit 302 includes a respective universal digital radiofrequency (RF) transceiver module 310, a universal digital transportinterface module 312, and a universal backplane module 314 tocommunicatively couple the universal digital RF transceiver modules 310and the universal digital transport interface module 312 to each other.The universal digital RF transceiver modules 310, the universal digitaltransport interface module 312, and the universal backplane module 314are “universal” in the sense that they can be used for multiplefrequency, power, or technology combinations, with appropriate softwarereconfiguration.

When analog RF signals are received and transmitted from the externalports 306 of a node unit 302, the node unit 302 includes a duplexingmodule 316 for each external port 306 (FIG. 3B). Each duplexing module316 is configured to enable bi-directional communication over a singleexternal port 306 and to isolate the RF signals coming from the poweramplifier module 320 to prevent receiver desensitization in theuniversal digital RF transceiver module 310.

Each duplexing module 316 comprises a filter element to filter out oneor more signals in one or more frequency bands and is configured tosupport either frequency-divisional duplexing (FDD) or time-divisionduplexing (TDD). Each FDD duplexing module 316 comprises at least oneduplexing filter element that filters first signals from second signals.The first signals are communicated from the respective external port 306(directly or via an optional universal combining harness module 318described below and shown in FIG. 3A) to an input of a respectiveuniversal digital RF transceiver module 310. The second signals arecommunicated from an output of the power amplifier module 320 used inthe respective universal digital RF transceiver module 310 to respectiveexternal port 306 (directly or via the optional universal combiningharness module 318).

Each TDD duplexing module 316 comprises at least one switching elementthat has a common port that is coupled to the respective external port306 (either directly or via the optional universal combining harnessmodule 318), an output port coupled to an input of a respectiveuniversal digital RF transceiver module 310, and an input port coupledto an output of the power amplifier module 320 used in the respectiveuniversal digital RF transceiver module 310. The switching element isconfigured to selectively couple either the input port or the outputport to the common port under the control of a timing signal. The timingsignal can be provided to the switching element from a system controller322, the respective universal digital RF transceiver module 310, or theuniversal backplane module 314.

Each duplexing module 316 is designed for a particular frequency rangeand technology (that uses either FDD or TDD).

An optional universal combining harness module 318 (shown in FIG. 3A)can be used to combine all of the output signals output by the universaldigital RF transceiver modules 310 (via the respective duplexing modules316) and provide the combined output signals to the external port 306and to provide the input signals received on the external port 306 to arespective input of all of the universal digital RF transceiver modules310 (via the respective duplexing modules 316). The universal combiningharness module 318 is “universal” in the sense that the combiningharness module 318 is configured as a wideband combiner to combinesignals having any and all possible frequency bands supported by thesystem 300.

If the universal combining harness module 318 is used, an external port306 is implemented by the universal combining harness module 318. If theuniversal combining harness module 318 is not used, the external ports306 are implemented by the duplexing modules 316.

Each power amplifier module 320 is configured to amplify an analog RFsignals output on the associated external port 306 to a desired outputpower and is configured to operate in a particular frequency range andoutput power range. The various power amplifier modules 320 can be havedifferent power classes and support different frequency bandwidths dueto amplification technology limitations. Each power amplifier module 320is configured to be connected to a universal digital RF transceivermodule 310 in order to receive an output from that universal digital RFtransceiver module 310.

In one some aspects, the duplexing modules 316 and the power amplifiermodules 320 may be the only modules that are limited to a subset of thepossible RF bands handled in the system 300.

Also, in some aspects, the power amplifier modules 320 cover a wider RFbandwidth than the duplexing modules 316 and can be connected to a setof duplexer filters via a splitter harness.

Each node unit 302 is configured to generate, from the input signal itreceives on each of its external ports 306, a respective stream ofdigital samples. Also, each node unit 302 is configured to generate, foreach of its transport ports 308 that is coupled to another node unit302, a respective transport signal that includes one or more of thestreams of digital samples generated from the inputs signals received onthe external ports 306.

In one aspect digital samples comprises digital in-phase and quadrature(IQ) samples. Other examples can be implemented in other ways.

Each universal digital RF transceiver module 310 is configured toperform the digital processing associated with generating a stream ofdigital samples from the respective input signal received on therespective external port 306 and is configured to perform the digitalprocessing associated with generating a respective output signal for therespective external port 306 from the stream of digital samples providedto the digital RF transceiver module 310 from the universal backplanemodule 314. Optionally, in some aspects, one or more of the digital RFtransceiver modules 310 can include base station modems (e.g., BTSmodems) or secondary Node B modems to drive the digital transceiver andto communicate with wireless terminal devices.

The universal digital transport interface module 312 is configured totransmit and receive streams of digital samples to and from a respectivenode unit 302 coupled to the other end of the transport communicationlink attached the associated transport port 308. Also, as noted below,in some aspects, the universal digital transport interface modules 310combines and separates the various streams of digital samples.

The universal backplane module 314 is configured to route digitalstreams of digital samples to and from the digital transceiver RFmodules 310 and the various inputs and outputs of the digital transportinterface module 312.

In some aspects, the universal backplane module 314 is implemented as anactive backplane that is configured (in a software configurable manner)to combine, for each transport port 308, the digital samples for one ormore streams and route, in a software configurable manner, the combineddigital samples to an appropriate input of the universal digitaltransport interface module 312. Also, in such an aspect, the universalbackplane module 314 is configured to separate, in a softwareconfigurable manner, the streams of digital samples received on eachtransport port 308 and route, in a software configurable manner, theseparate digital samples to the appropriate universal digital RFtransceiver modules 310.

Each universal digital RF transceiver module 310 filters the respectiveinput signal to output a frequency band of interest, levels the filteredsignal (for example, by adjusting its gain), down-converts the filteredsignal to an intermediate frequency (IF) or to baseband, digitizes thedown-converted signal to produce real digital samples, digitallydown-convert the real digital samples to produce digital in-phase andquadrature (IQ) samples, which are output to the universal backplanemodule 314. In such aspects, the universal digital RF transceiver module310 can also be configured to filter, amplify, attenuate, and/orre-sample or decimate the digital IQ samples to a lower sample rate. Insuch aspects, the universal backplane module 314 combines, for eachtransport port 308, the digital samples for one or more streams (forexample, by framing the digital samples together) and routes thecombined digital samples to an appropriate input of the universaldigital transport interface module 312.

In such aspects where the universal backplane module 314 is implementedas an active backplane, similar processing is performed in the otherdirection in order to generate a respective output signal for eachexternal port 306 from a stream of digital samples provided from thedigital transport interface module 312. The universal backplane module314 separates the combined streams of digital samples received on eachtransport port 308 from the associated transport communication link and,for each universal digital RF transceiver module 310, digitally sumstogether corresponding digital IQ samples provided from the varioustransport ports 308 and provides the summed digital IQ samples to theappropriate universal digital RF transceiver module 310. Each universaldigital RF transceiver module 310 digitally up-converts the summeddigital IQ samples provided to it to produce real digital samples. Eachuniversal digital RF transceiver module 310 can also filter, amplify,attenuate, and/or re-sample or interpolate the digital IQ samples.

Either the universal digital RF transceiver module 310 or the poweramplifier module 320 coupled thereto performs a digital-to-analogprocess on the real samples provided in order to produce an IF orbaseband analog signal and up-converts the IF or baseband analog signalto the desired RF frequency.

In some aspects, the power amplifier module 302 is configured to receivethe digital samples from the associated universal digital RF transceivermodule 310, convert the digital samples to an analog signal, up-convertthe analog signal to an appropriate RF frequency, and amplify the analogRF signal, the result of which is output to the respective external port306. Digital or analog pre-distortion can also be performed prior toamplification to realize more usable power from the amplifier (forexample as the output power increases). In other aspects, each universaldigital RF transceiver module 310 is configured to convert the digitalsamples to an analog signal, up-convert the analog signal to anappropriate RF frequency, and output the resulting analog RF signal tothe power amplifier module 320, which amplifies the analog RF signal asdescribed above. In such aspects, digital pre-distortion can beperformed by the universal digital RF transceiver module 310.

In some aspects, the universal backplane module 314 is implemented as apassive backplane that routes one or more streams of digital samplesfrom the outputs of the universal digital RF transceiver modules 310 tothe inputs of the universal digital transport interface module 312 androutes one or more streams of digital samples from the outputs of theuniversal digital transport interface module 312 to the inputs of theuniversal digital RF transceiver modules 310. In such aspects where theuniversal backplane module 314 is implemented as a passive backplane,the universal digital transport interface modules 312 combines andseparates the various streams of digital samples, and each universaldigital RF transceiver module 310 is configured to digitally sumcorresponding digital IQ samples provided from the universal digitaltransport interface module 312 via the universal backplane module 314.

In some example, the system 300 is configured to intelligently detectand understand how the modules 310, 312, 314, 316, 318, and 320 areconnected to each other to visualize the complete system 300 and adjustit according to pre-defined rules.

Each module 310, 312, 314, 316, 318, and 320 includes a moduleidentification (ID) 324 that identifies the module and its capabilities.The module ID 324 can be implemented in various ways. For example, themodule ID 324 can be stored in a non-volatile memory within the module.The system controller 322 is coupled to one or more interfaces orreaders 326 that are configured to read the module ID 324 from eachmodule 310, 312, 314, 316, 318, and 320.

For both off-air repeaters and digital antenna systems, modules 310,312, 314, 316, 318, and 320 can be used in a way to build up the system300 on-the-fly according to the required needs. This may reduce thetotal number of the individual modules that a manufacture needs to keepin stock and can offer flexibility to upgrade and exchange frequencybands in the field for existing installations.

The system 300, as assembled, can support a combination of RF bands. Thesystem 300 can have in-situ means, such as the system controller 322, todetermine its combination of modules and mechanical systemconfiguration. The system 300 can in a self-organizing manner, definethe parameters or configure of at least one of the following: out of themultitude of controllers in the various modules, one single controllerthat takes over local system control tasks, the configuration of signalrouting, the self-calibration of RF paths in RF gain, RF power overfrequency, RF band, or RF connector, the fan collaboration in the activecooling of the system, and the self-detection of frequency dependencyfor passive elements such as the duplexing module 316 and the universalcombing harness module 318.

Examples of variants of the various modules are shown in FIG. 3C. Thesystem 300 may be an open system that allows new variants of modules orelements to be added to the list of possible modules or elements and forthem to be used in new configurations without the prior need to changethe software. It can be achieved by exchanging element/moduledescriptions and technical data files that the system software is ableto read and interpret.

The overall functionality in other examples can be split differentlythan above. For example, each power amplifier module 320 may not belimited to one link only. Parts of the universal digital RF transceivermodule 310 functionality may instead be realized in the power amplifiermodule 320 (e.g. amplification of the received RF signal coming from theduplexing module 316 or the conversion of RF into digital signals).

Although the universal digital RF transceiver modules 310 are describedabove as being to interface with external equipment using an analog RFinterface, it is to be understood that the universal digital RFtransceiver modules 310 can be configured to interact with externalequipment using a digital interface, in which case the digital RFtransceiver module 310 is configured to convert between the digitalinterface format used for such external equipment and a digital formatsuitable for communication over the digital transport links. Forexample, in some examples, a distributed base station component (such asa baseband unit (BBU)) can be coupled to a universal digital RFtransceiver module 310 using a digital IQ interface (for example, aCommon Public Radio Interface (CPRI) digital IQ baseband interface).Other digital RF formats can be used.

FIG. 4 is a block diagram of one example of a distributed antenna system400 built with the modules and nodes units of FIGS. 3A-3C.

In the example shown in FIG. 4, the node units 302 are arranged andconfigured as a distributed antenna system (DAS) 400. In the exampleshown in FIG. 4, one of the node units 302 is arranged and configured tofunction as a master unit 401 of the DAS 400, and multiple other nodeunits 302 are arranged and configured to function as remote antennaunits 403 of the DAS 400. The multiple remote antenna units 403 arelocated remotely from the master unit 401. The master unit 401 iscommunicatively coupled to each of the remote antenna units 403 over arespective transport communication link (which is implemented using apair of optical fibers 405 in this example). Each pair of optical fibers405 is coupled to a respective transport port 308 of the master unit 401and a transport port 308 of a respective remote antenna unit 403.

In this example, the master unit 401 is communicatively coupled tomultiple base stations 407 using an analog RF interface. Each basestation 407, in this example, is coupled to a respective one of theexternal ports 306 of the master unit 401 using a respective one or morecables.

In this example, each remote antenna unit 403 is communicatively coupledto a respective one or more antennas 409. The antennas 409 are coupledto an external port 306 of the respective remote antenna unit 403. Inthis example, each external port 306 is implemented by a respectiveduplexing module 316 in the master unit 401.

In this example, the master unit 401 generates one or more downstreamstreams of digital in-phase/quadrature (IQ) samples from the analogdownstream RF input received from a base station 407 on each externalport 306 of the master unit 401.

In the downlink direction, transmit signals from the base stations 407can be fed to respective digital RF transceiver modules 310 in themaster unit 401 via a respective duplexing module 316. As described,above each digital RF transceiver module 310 generates, from thetransmit signal it receives, a respective stream of digital samples,which are provided to the universal backplane module 314 in the masterunit 401. In this example, the universal backplane module 314 in themaster unit 401 combines the digital samples from all of the universaldigital RF transceiver modules 310 (for example, by framing the digitalsamples together) and provides the combined digital samples to anappropriate input of the digital transport interface module 312 for eachtransport port 308, which optically transmits the combined digitalsamples to a respective one of the remote units 403.

The digital transport interface module 312 in each remote unit 403receives the optically transmitted downstream combined digital samplesand provides the combined digital samples to the universal backplanemodule 314 in the remote unit 403. The universal backplane module 314separates the combined digital samples for the various streams androutes each stream to an appropriate digital RF transceiver module 310in the remote unit 403, which (along with the associated power amplifiermodule 320) generates a respective transmit analog RF signal. Thevarious transmit analog RF signals are combined by the universal combinghardness module 318 in the remote unit 403 and the resulting combinedsignal is radiated from the one or more antennas 409.

In an uplink direction, at each remote unit 403, combined receive RFsignals are received via the associated antenna 409 on the external port306. The combined receive RF signals are split to the individualfrequency bands via the universal combiner harness module 318 and theduplexing modules 316 and the resulting individual receive RF signalsare provided to respective digital RF transceiver modules 310 in theremote unit 403. As described, above each digital RF transceiver module310 in the remote unit 403 generates, from the receive signal itreceives, a respective stream of digital samples, which are provided tothe universal backplane module 314 in the remote unit 403. In thisexample, the universal backplane module 314 in each remote unit 403combines the digital samples from all of the universal digital RFtransceiver modules 310 (for example, by framing the digital samplestogether) and provides the combined digital samples to an appropriateinput of the digital transport interface module 312 for the transportport 308, which optically transmits the combined digital samples to themaster unit 401.

Each digital transport interface module 312 in the master unit 401receives the optically transmitted upstream combined digital samples andprovides the combined digital samples to the universal backplane module314 in the master unit 401. The universal backplane module 314 separatesthe combined digital samples for the various streams from each of theremote units 403, and, for each universal digital RF transceiver module310, digitally sums together corresponding digital samples provided fromthe various remote units 403 and routes the summed digital samples tothe appropriate universal digital RF transceiver module 310, which(along with the associated power amplifier module 320) generates arespective receive analog RF signal that is output to the appropriatebase station 407.

Alternatively, some or all base stations 407 can be coupled to themaster unit 401 using a digital interface (for example, a digital IQformat or other digital RF format).

FIG. 5 is a block diagram of one example of a repeater 500 built withthe modules and nodes units of FIGS. 3A-3C.

In the example shown in FIG. 5, the node units 302 are arranged andconfigured as an off-the-air repeater 500. In the example shown in FIG.5, one of the node units 302 is arranged and configured to function as adonor unit 501 of the repeater 500, and multiple other node units 302are arranged and configured to function as coverage units 503 of therepeater 500. The multiple coverage units 503 are located remotely fromthe donor unit 501. The donor unit 501 is communicatively coupled toeach of the coverage units 503 over a respective transport communicationlink 505 (which is implemented using copper cable links (e.g., CATcables)). Each cable 505 is coupled to a respective transport port 308of the donor unit 501 and a transport port 308 of a respective coverageunit 503.

The processing performed in the donor units 501 and the coverage units503 is similar to that performed by the master unit 401 and the remoteunits 403 of FIG. 4, except that in the example shown in FIG. 5, RFsignals transmitted over the air by the base stations 507 are combinedin the wireless channel. The combined transmit RF signals are receivedvia one or more donor antennas 511 and provided to an external port 306of the donor unit 501. The combined transmit RF signals are split to theindividual frequency bands via the universal combiner harness module 318and the duplexing modules 316 in the donor unit 501 and the resultingindividual transit RF signals are provided to respective digital RFtransceiver modules 310 in the donor unit 501. Also, as the couplingloss to the individual base stations 507 may be higher, the poweramplifiers modules 320 in the donor node 501 can be selected so as toprovide more output power compared to the power amplifier modules 320used in the master unit 401 shown in FIG. 4.

Referring again to FIGS. 3A-3C, active modules (e.g., universalbackplane module 314, universal digital RF transceiver modules 310,power amplifier modules 320, digital transport interface modules 312,and any FDD/TDD duplexing modules 316) may be permanently powered-up andare often communicating with the system controller 322 through aninternal bus (e.g., a bus implemented using PC, RS485, Ethernet, etc.).When a different new active module is added to a previously empty slotor position in a node unit 302 or an existing active module is removedand replaced with a different active module, that newly added activemodule can be detected by the system controller 322 due to the ongoingbus communication and the detection of a different module ID 324.

Passive modules (e.g., FDD duplexing module 316 and the universalcombiner harness module 318) may not be detected in the same manner asactive modules as it may not be cost effective to supply voltage to anotherwise passive module just to communicate with a non-volatile memoryto determine the module ID 324 of that module. The following is anexample of alternative mechanisms to enable the system to identifypassive modules (or other types of modules, if desired):

In some examples, each of the modules can be equipped with a bar codelabel that that includes ID information. In the case of a new module tobe inserted or an existing module to be swapped, a system-wide processcan be used to scan the modules. For example, the process can start anoptical detector (e.g., camera) 326 inside the system or can establish acommunication link to external equipment (e.g., a mobile device such asa smartphone) with an optical detector 326 that is able to scan themodule IDs 324 of the modules.

In other examples, each of the modules can be equipped with a quickresponse (QR) code label that includes the ID information. In the caseof a new module to be inserted or an existing module to be swapped, asystem-wide process can be used to scan the modules. For example, theprocess can start an optical detector (e.g., camera) 326 inside thesystem or can establish a communication link with external equipmentwith an optical detector 326 (e.g., a mobile device such as asmartphone) that is able to scan the module IDs 324 of the modules.

In still other examples, each of the modules can be equipped with anRFID (radio-frequency identification) chip or tag that includes themodule ID 324. In the case of a new module to be inserted or an existingmodule to be swapped, a system-wide process can be used to scan themodules. The process can begin with an RFID scanner 326 inside thesystem or a communication link to external equipment with an RFIDscanner to read the module IDs 324 from the RFID tags of the modules.

In other examples in which the passive modules do not have anyidentification, such as bar codes, QR codes, or RFID tags, measurementscan be used to determine which modules are connected. One example of asystem for doing this is shown in FIG. 6. As shown in FIG. 6, the systemcontroller 322 can start an RF scanning process for each possiblesupported frequency range in a power amplifier module 320 frequencyrange. In the example shown in FIG. 6, the node unit 302 furtherincludes a continuous wave (CW) tone generator 330 that can inject a CWtone into the various signal paths of the node unit 302 starting at theinput of each power amplifier module 320. A respective coupler 332 isprovided at the output of each power amplifier module 320 and input tothe corresponding duplexer module 316. Another coupler 334 is providedat the common output of the universal combining hardness module 318. Thecouplers 332 and 334 are connected to a power detector 336, which canselectively determine the power level at any of the couplers 332 and334.

The system controller 322 can cause the CW tone generator 330 to sweepthe CW tone in certain frequency steps associated with various frequencyband supported by the modules. The power detector 336 can measure thepower level at each of the first detectors 332 before each duplexingmodule 316 and at the second power detector 334 after the universalcombiner harness module 318. For frequencies within the passband, thedetected output power at the second coupler 336 should be close to therated output power, whereas, for frequencies within the stop band, theoutput power should be much lower. By repeating the CW tone sweep foreach individual transmit link, the multiple pass bands can be detected.

In some examples, the system can detect new frequency bands and, ratherthan adapting via software, can output information that identifies tosoftware the frequency bands that is supported by the modules.

The foregoing description of the examples, including illustratedexamples, has been presented only for the purpose of illustration anddescription and is not intended to be exhaustive or to limit the subjectmatter to the precise forms disclosed. Numerous modifications,adaptations, and uses thereof will be apparent to those skilled in theart without departing from the scope of this disclosure. Theillustrative examples described above are given to introduce the readerto the general subject matter discussed here and are not intended tolimit the scope of the disclosed concepts.

What is claimed is:
 1. A node unit for a scalable telecommunicationssystem, the node unit comprising: a plurality of universal digital RFtransceiver modules, each of which is configured to communicativelycouple the node unit to respective external equipment; one or moreuniversal digital transport interface modules, each of which isconfigured to communicatively couple the node unit to a respectivetransport link; a universal backplane module communicatively coupled tothe universal digital RF transceiver modules and to the universaldigital transport interface modules; and a system controller; whereinthe node unit is configured to have inserted therein a respective poweramplifier module and duplexing module for each universal digital RFtransceiver module; wherein the node unit is configured tocommunicatively couple an input of each power amplifier module to anoutput of the respective universal digital RF transceiver module;wherein the node unit is configured to communicatively couple eachuniversal digital RF transceiver module to the respective externalequipment via the respective duplexing module; wherein at least onemodule comprises a respective module identifier; wherein the systemcontroller is configured to read the at least one module identifier andto configure the operation of at least one of the universal digital RFtransceiver modules, the universal digital transport interface modules,and the universal backplane module based on the at least one moduleidentifier.
 2. The node unit of claim 1, wherein the node unit isfurther configured to be used with a universal combiner harness that iscoupled to each of the duplexing modules.
 3. The node unit of claim 1,wherein each universal digital RF transceiver module is configured toreceive a first input from the respective external equipment and outputrespective first digital samples associated with the respective firstinput to the universal backplane module; wherein each universal digitaltransport interface module is configured to receive respective secondsamples from the universal backplane module and to output a respectivefirst output to the respective transport link; wherein the respectivesecond samples received at each universal digital transport interfacemodule are derived from the respective first samples output from one ormore of the universal digital RF transceiver modules; wherein eachuniversal digital transport interface transceiver module is configuredto receive a second input from the respective transport link and outputrespective third digital samples associated with the respective secondinput to the universal backplane module; wherein each universal digitalRF transceiver module is configured to receive respective fourth samplesfrom the universal backplane module and to output a respective secondoutput to the respective external equipment; and wherein the respectivefourth samples received at each universal digital RF transceiver moduleare derived from the respective third samples output from one or more ofthe universal digital transport interface modules.
 4. The node unit ofclaim 1, wherein the universal backplane module comprises at least oneof an active universal backplane module and a passive universalbackplane module.
 5. The node unit of claim 1, wherein the systemcontroller is configured to configure the operation of at least one ofthe universal digital RF transceiver modules, the universal digitaltransport interface modules, and the universal backplane module based onthe at least one module identifier by doing at least one of: identifythe system controller among a number of controllers in various modules;configuring routing in the universal backplane module; configuring asignal path in at least one of the universal digital RF transceivermodules; configuring cooling of the node unit; and detecting a frequencyrange of at least one duplexing module.
 6. The node unit of claim 4,wherein configuring a signal path in at least one of the universaldigital RF transceiver modules comprises configuring at least one of anRF frequency band for the signal path, a gain in the signal path, aconnector in the signal path, and a power level in the signal path. 7.The node unit of claim 1, wherein each power amplifier module, duplexingmodule, universal digital RF transceiver module, universal digitaltransport interface module, and universal backplane module comprises arespective module identifier.
 8. The node unit of claim 1, wherein thenode unit is configured to determine a respective frequency rangeassociated with each duplexing module.
 9. The node unit of claim 1,wherein the external equipment comprises at least one of: a monolithicbase station element, a distributed base station element,antenna-related equipment, and a core-network element.
 10. The node unitof claim 1, wherein each duplexing module comprises at least one of afrequency division duplexing (FDD) duplexing module and a time divisionduplexing (TDD) module.
 11. The node unit of claim 1, wherein eachmodule identifier is stored in at least one of: a memory device, a barcode label, a quick response (QR) code label, and a radio frequencyidentifier (RFID) chip.
 12. The node unit of claim 1, wherein the nodeunit comprises a reader configured to read a module identifier from atleast one of: a memory device, a bar code label, a quick response (QR)code label, and a radio frequency identifier (RFID) chip.
 13. The nodeunit of claim 1, wherein the node unit is configured to function as atleast one of: a master unit of a distributed antenna system, a remoteunit of a distributed antenna system, a donor unit of a repeater, and acoverage unit of a repeater.